1. Field of the Invention
The present invention relates to a microfluidic device with network micro channels, and more particularly, to a microfluidic device applicable to biomedical analyses.
2. Description of the Related Art
Microfluidic devices integrated with biochips are getting more and more popular lately, because they provide better operational ways for biological or medical syntheses and analyses. Microfluidic devices are characterized by small size and an automatic diversion function, thus they have plenty of advantages, namely fewer amounts of reagents, miniaturization, fast sensing response, good integration, etc. They minimize manual operations, save reagents and rapidly process voluminous biological data transmitted in parallel, compared with conventional biomedical analytical methods.
By a microfluidic device, it means infusing microliters, or even nanoliters, of liquid into a substrate with micro channels, and making the liquid undergo an intended reaction inside the micro channels by means of a mechanical or non-mechanical pump. To build this miniature structure, it requires a micro electromechanical fabrication method, that is, a fabrication process that involves performing thin film growth, photolithography and etching on a substrate repeatedly. Instead of being limited to a silicon wafer, the substrate can also be glass, quartz or polymer. Polymers from which the substrate can be made include PMMA (polymethylmethacrylate), PC (polycarbonate), PDMS (polydimethylsiloxane), etc.
In U.S. patent application Ser. No. 10/438,527, entitled “Fabrication Method of Three-Dimensional Micro Structures” he put forth, the principal inventor of the present invention discloses a fabrication process for a real three-dimensional micro channel structure, wherein it involves the lithographic technique of a thick film photoresist, forming a micro structure by controlling the exposure dosage of UV light, and thus cutting the manufacturing cost and simplifying the fabrication process. Hence, the proposed fabrication process is superior to the conventional fabrication process. In general, microfluidic devices are restricted by their fabrication method to such an extent that they have only two-dimensional micro channels, thus it is impossible to connect micro channels that belong to different networks in parallel. Hence, these microfluidic devices have their limitations, as far as the scope of their applications and their operating methods are concerned.